lockdep: add lock_class information to lock_chain and output it

[net-next-2.6.git] / kernel / lockdep.c

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index a796f1f38ac5b0c625c37a0d81cb23665d7f5e1e..7553a28b99cdd3b832eec916b5f3a2f9ea84157a 100644 (file)
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1459,7 +1459,7 @@ out_bug:
 
 unsigned long nr_lock_chains;
 struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
-atomic_t nr_chain_hlocks;
+int nr_chain_hlocks;
 static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
 
 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
@@ -1481,7 +1481,7 @@ static inline int lookup_chain_cache(struct task_struct *curr,
        struct list_head *hash_head = chainhashentry(chain_key);
        struct lock_chain *chain;
        struct held_lock *hlock_curr, *hlock_next;
-       int i, j, n;
+       int i, j, n, cn;
 
        if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
                return 0;
@@ -1540,9 +1540,15 @@ cache_hit:
        }
        i++;
        chain->depth = curr->lockdep_depth + 1 - i;
-       n = atomic_add_return(chain->depth, &nr_chain_hlocks);
-       if (unlikely(n < MAX_LOCKDEP_CHAIN_HLOCKS)) {
-               chain->base = n - chain->depth;
+       cn = nr_chain_hlocks;
+       while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) {
+               n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth);
+               if (n == cn)
+                       break;
+               cn = n;
+       }
+       if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
+               chain->base = cn;
                for (j = 0; j < chain->depth - 1; j++, i++) {
                        int lock_id = curr->held_locks[i].class - lock_classes;
                        chain_hlocks[chain->base + j] = lock_id;